Why Does Time Affect OCI

[Rand]

in warranty some recommendations are as low as 3mo 3000mi for severe service.

and severe service is really pretty much anything except optimal conditions.


My driving qualifies as severe service which is why I change twice a year with a syn.

 

[John_K]

Originally Posted By: CATERHAM
Originally Posted By: 1993_VG30E_GXE
Can someone explain to me why they say for eg. 12,000 KM or 6 MONTHS Whatever comes first.

How is it that the time affects the OCI, when oil can be sitting in containers for 5 yrs and not degrade much. Why is it that as soon as it goes in the engine we are on the 6 Months count down?


I don't know any manufacturer that has a time limit as short as six months.


For both vehicles below the manual says "7,500 miles or six months, which ever comes first."

John

 

[Jim Allen]

I hasten to add to my earlier comments that warranty requirements trump all other factors. Everything I own is long out of warranty, so it does not enter into my thinking all that much.

 

[Gary Allan]

Originally Posted By: John_K
Originally Posted By: CATERHAM
Originally Posted By: 1993_VG30E_GXE
Can someone explain to me why they say for eg. 12,000 KM or 6 MONTHS Whatever comes first.

How is it that the time affects the OCI, when oil can be sitting in containers for 5 yrs and not degrade much. Why is it that as soon as it goes in the engine we are on the 6 Months count down?


I don't know any manufacturer that has a time limit as short as six months.


For both vehicles below the manual says "7,500 miles or six months, which ever comes first."

John


Yeah. Just about any domestic without an OLM (or equivalent) is 6months. The mileage can be 3750-7500 miles depending on manufacturer.

Severe service can also include non OLM equipped cars that consume much more fuel than they accumulate in mileage.

 

[CATERHAM]

"severe service is pretty much anything other than optimal conditions"

I don't know what that means but I think the OP's question has been answered.

 

[ThirdeYe]

Originally Posted By: Gary Allan
Originally Posted By: John_K
Originally Posted By: CATERHAM
Originally Posted By: 1993_VG30E_GXE
Can someone explain to me why they say for eg. 12,000 KM or 6 MONTHS Whatever comes first.

How is it that the time affects the OCI, when oil can be sitting in containers for 5 yrs and not degrade much. Why is it that as soon as it goes in the engine we are on the 6 Months count down?


I don't know any manufacturer that has a time limit as short as six months.


For both vehicles below the manual says "7,500 miles or six months, which ever comes first."

John


Yeah. Just about any domestic without an OLM (or equivalent) is 6months. The mileage can be 3750-7500 miles depending on manufacturer.

Severe service can also include non OLM equipped cars that consume much more fuel than they accumulate in mileage.


My car is 7,500 miles or 6 months as well for normal service. 3,750 miles/3 months for severe.

 

[Bill in Utah]

Originally Posted By: CATERHAM


I don't know any manufacturer that has a time limit as short as six months. Nevertheless, the time limit is to conservatively cover the worst case scenario which is very short trips with the oil not getting up to temp'.
You can certainly go on mileage alone if you don't do predominately short trips particularly in the winter.
There are plenty of high mileage 2 and 3 year long UOA's that are excellent.


Toyota, Nissan, Dodge, Subaru to name a few. On some models the OCI is as short as 3k or 3months. Subaru has 3,750 or 4 months for severe service.

 

[Ken2]

The time the oil sits in the sump makes very little difference. I've done oil analyses on industrial engines where the oil has been in service for years, and the oil remained good. The crankcase oil in a very large diesel is a lifetime fill, 20 years or more. A midsized engine like a locomotive sized engine is good for years as long as the oil is properly filtered or centrifuged and contaminants don't get into the oil. I've been with 2500 kW engines (3350 hp) that burned heavy fuel oil with 3% sulfur, and the oil was still good after two years when I moved on. These engines had about a 50% duty cycle...ran maybe 15 days (24 hour days) a month.

Operating conditions kill the oil. Short, cool runs where the oil never gets normally warm is about as hard on the oil as very hot & heavy runs. The oil life monitors are programmed in exactly this way. If I ran an engine normally warm for an hour or more once a month (like a look-at-me car that hardly gets on the road), I'd probably change that oil every five years just so I remember how to do it.

 

[firemachine69]

No kidding. I think I've done about four full-fledged highway trips since I purchased my Yaris two years ago. My "cold engine" light goes off a quarter mile from where I report to work. I'm still blowing cold air in winter (and hot A/C in the summer). Most trips are under ten miles, and those are "long outings".

My Yaris has a maximum six-month OCI interval, and all my UOA's from Blackstone come back as decent, barring some minor fuel-dilution from starting the car to roll it up on the ramps.

 

[1993_VG30E_GXE]

Thanks everyone - this clears up the issue. Reason I'm asking is because i'm on 6000KM OCI (3 Mo.) right now, and I want to switch to AMSOIL SERIES 3000 5W30 Syn, to put in my 93 Nissan Maxima, as this has higher ZDDP than SM.

They state OCI of 1 yr for severe service and 24,000 KM. I'm going to go with half that, but keep the 1 yr rule.

 

[Andyge]

I have a 2006 Sentra and I use AMSOIL in it and I go 1 year OCI.

I have been do this for 3 1/2 years now.

Andy

 

[1993_VG30E_GXE]

Bad news, can't go with AMSOIL - pricing is bad, so i'll look at the Shell Rotella T. Please see my other post on Shell Rotella T.

 

[Andyge]

I have a 93 Ford Ranger and I only put on 3,000 a year.

I change my oil every 6 MONTH.

is this over kill?

Andy

 

[Hokiefyd]

Andy, I don't think so. That's similar to the miles/year on my Dodge and my OCI as well. I change oil in the Dodge every 2k miles, just to make it easy. I put on between 3-5k miles per year on it, so it's about every 6 months, like what you're doing.

 

[Norm Olt]

Originally Posted By: Andyge
I have a 93 Ford Ranger and I only put on 3,000 a year.

I change my oil every 6 MONTH.

is this over kill?

Andy



Yes, IMHO. I'd just change it once a year at the beginning of the really cold (MN) times. Your truck's body & frame will rust out to a block of swiss cheese before 3K/1 year OCI's destroy the engine.

Cheers!

 

[Andyge]

Norm thanks My Dad said the same thing.

Andy

 

[exls]

Originally Posted By: Norm Olt
Originally Posted By: Andyge
I have a 93 Ford Ranger and I only put on 3,000 a year.

I change my oil every 6 MONTH.

is this over kill?

Andy



Yes, IMHO. I'd just change it once a year at the beginning of the really cold (MN) times. Your truck's body & frame will rust out to a block of swiss cheese before 3K/1 year OCI's destroy the engine.

Cheers!


I might be in a different situation, I run about 3-5k a year in my integra and change it oil once a year and it came out like black pudding.

 

[JohnBrowning]

Some alloys suffer from more oxidation then others and th aditives in oil that prevent corrission wear do not last forever. In fact most oils have very weak forms of deffense against corrosive wear while sitting. It is a huge issues for car collectors that do not drive their queens that often and for seldom flown aircraft aka hanger queens!